2004 Black TL Base Auto,83,349miles.
Motor Stock
Optima Yellow D35 In Front and Optima Yellow 34 In Rear- Wired Positive to Positive and Negative To Negative with in-line Fuse.
Big 3 Wiring Done As Well
Aftermarket Speakers,HeadUnit, Amps(4chan and 2Chan) and one 8” 800watt Sub .




So for the past few weeks I’ve been wondering why all the warning lights on my Dash would come on at what I thought was just random times, which would then force/make the car go into some kinda slave/safety mode. It would just rev super high and I’d go to A max of 2-5mph with the pedal pushed to the floor.

i started off with thinking it was the battery, but I’d charge it for A day to check it with the multimeter and see that it was holding A good normal charge.
So after looking at all my notes I realized the electrical error would ALWAYS happen either after I started the car and sat in it for A little bit before driving, and then came to a stop or was at A slow speed for to long.
Or the problem would happen immediately when I’d try to start it or start it after working on the sound system/wiring for A few hours. I’d have the doors open with the battery still connected sometimes since I needed to find out certain functions with the wiring harnesses.

But this morning was the worst, to start I needed to jump the car to start it only after having it off for A few minutes while doing my deliveries for work(Many Short Trips/Distances).. Immediately the dash lights came on and it went into that safety mode, but then my Aftermarket Radio wouldn’t turn on, and then the dash lights turned off completely and the dash back light was quickly fading out with the gauges all at 0 while I was going 2-5mph. Then it shut off once I lost enough speed/momentum since I was going down A slight decline..

Any advice on what I should check or anything else I could check to possibly diagnose this to see what I’m up against or so I know what the actual damage is? Oh and any suggestions on Aftermarket or OEM high output alternators, that are drop in w/out any modifications needed to make it fit good?
Hopefully it is just the alternator, cause I’ve been wanting to get A high output aftermarket alternator to be able to handle my Aftermarket Sound System I’ve been currently slowly installing here and there.

 

Slow speeds makes me think it's potentially a slipping belt or poorly tensioned belt that makes your alternator not work. If i were you, I'd replace the drive belt, drive belt tensioner, and DENSO alternator (same as OEM brand but cheaper) and go from there.

 

Hey, thanks for the quick reply!

But I think the only reason for the super slow speed is because of some kind of mode or safety feature? It seems like it kicks on when it’s not getting A minimum amount of voltage. When I put in A battery that’s been charged for Ah day, the warning lights on the dash disappear and the car drives normal again

 

Alternators produce voltage, not receive them. When I said slow speed, I was referring to you idling or driving slowly. Slow engine speed/idle means that the engine is not spinning the alternator enough to charge the batteries (i.e. loose drive belt or not properly tensioned or just a bad alternator) In other words, your alternator is not producing enough power to charge both batteries.

Replace the above and report back

 

I know what you meant Mah bro, I brought up the speed that I was going because A higher speed/rpm will usually always help the alternator produce its maximum voltage that it’s rated at. Which is why the car was still able to run, even though really shitty with the radio off,gauges not working, and dash light dimming by the second and eventually turn off when I hit A stop lol.

But yeah, I had to remove the Alternator fan in order to change the bad alternator to An aftermarket 150amp one that I got from Napa Auto Parts.

Had to pull the trigger once I saw the alternator was only producing 8.6-8.8v at the battery when the car was turned on idling.

 

So while changing the alternator to the brand new one, I was shocked to see that the Front Motor Mount was completely toast!! I’m going to remove some covers in order to check the other 2 in the engine Bay. I already checked and the Hydraulic Mount is about 160$ and the rubber mount is about 70-80$. The rear hydraulic mount is also about 80$ if that needs to be changed as well! Any suggestions on brands or other specific aftermarket mounts for my TL?

Oh and here is the Tool that I use to check the status of my battery and charging system. I also have an older analog one that just has A regular meter for the battery/charging system but it’s kind of hard to get A good reading on anything besides the battery! This electronic digital analyzer is one of the best and cheapest meters I’ve come across!

 

That's actually the side motor mount, not the front. The front is right under the radiator in the front of the car.


they have a couple options here on Rock Auto: https://www.rockauto.com/en/catalog/...tor+mount,5552

 

Correct that you are lol, well let’s say it’s one of the front motor mounts haha? Yeah the one under the radiator doesn’t look like anything’s wrong with it, but I’m also only looking from the very top of it which isn’t letting me see it entirely.

Oh oh as for right now, when the car is fully on idling, I’m seeing A 14.4 voltage, I also made sure to switch into different gears while pressing the brake and the voltage will fluctuate slightly at the time of switching gears but levels back out in like half Ah second.

So im thinking that the alternator was the only culprit this time, none of the VSA,Air Bag, battery, or check engine light comes on anymore and I don’t get to experience that oh so fun safety
mode for now haha!

But it I still need to install an isolator on my secondary optima D34 in the rear of the car, and take care of that busted mount

 

You're welcome

 

appreciate it Mah bro. Right on for the link to!

 

sorry to hijack, but about those rock auto engine mounts, do they increase engine vibration? there's a lot of info on poly mounts and engine vibration, but about this OEM like aftermarket mount, anybody had experience with them? thanks in advance